Information processing apparatuses are equipped with various cooling mechanisms.
Some information processing apparatuses have structures, in each of which a plurality of units are detachable and attachable in a single apparatus so as to adapt to advance and increase in functionality. In information processing apparatuses with such structures, for example, the front of a housing, where a unit is detached and attached, is regarded as the air inlet side while the rear of the housing is regarded as the air outlet side.
Performance of information processing apparatuses has been growing and the calorific values of installed electronic components have been increasing as well. In an information processing apparatus, therefore, it is desirable that not only integrated circuits, such as a central processing unit (CPU) and memory, but also a power supply unit and other electronic components be supplied with a sufficient amount of cold air. However, in an information processing apparatus in which the front of a housing, where a unit is detached and attached, is regarded as the air inlet side while the rear of the housing is regarded as the air outlet side, normally, air that has passed through a detachable and attachable unit flows to the rear face of the housing and thus, no low-temperature cooling wind is supplied to the electronic components located more downstream than the unit. To enable low-temperature cooling wind to be supplied to the electronic components located more downstream than the unit even in the information processing apparatus in which the front of the housing, where the unit is detached and attached, is regarded as the air inlet side while the rear of the housing is regarded as the air outlet side, for example, it is conceivable to arrange an air inlet duct that bypasses the unit. Arranging an air inlet duct that bypasses the unit enables low-temperature cooling wind to be supplied to the electronic components located further downstream than the unit. However, arranging an air inlet duct that bypasses the unit decreases space that the unit may occupy. Thus, in an information processing apparatus with a structure where an air inlet duct that bypasses a unit is arranged, the number or sizes of components that may be installed in the unit against the amount of the cooling wind that may be provided through the air inlet duct are traded off.
The following is a reference document.    [Document 1] Japanese Laid-open Patent Publication No. 2008-251067.